In recent years, the popularity of small local area networks (LANs) having many "intelligent" computers interlinked by a local interfacing network has dramatically increased. This popularity is fueled by the rapidly evolving complexity and sophistication of computers and supporting software. Today's computers have tremendous processing speeds and storage resources that were not available a decade ago. As a result, LANs have become one preferred structure for small and medium size companies, often times replacing the mainframe architecture consisting of many "dumb" terminals connected to a centralized computer and storage center. Even large companies are shifting reliance from mainframes to the more flexible LANs.
As LANs evolve to support more and more users, there is an increasing need to provide storage systems having sufficient storage capacity to accommodate a large volume of data being stored by multiple users. These storage systems must be capable of timely handling an increasing number of I/O requests generated by the multiple users, while minimizing the time that such shared resources appear busy. Concurrent with these two goals is the ever present desire to provide storage systems that are not unduly expensive.